Method and apparatus for tinning connecting rod bearings



March 21, 1933. w. J FlEGEL 1,902,770

METHOD AND APPARATUS FOR TINNING CONNECTING ROD BEARINGS Filed Sept. 16, 1929 I 3 Sheets-Sheet 1 mvm'on A i/21510715404 ATTORNEYS March 21, 1933. w. J. FIEQEL 1,902,770

METHOD AND APPARATUS FOE TINNING CONNECTING ROD BEARINGS ATTORNEYS March 21, 1933.

METHOD AND APPARATUS FOR TINN I NG CONNECTING ROD BEARINGS Filed Sept. 16, 1929 3 Sheets-Sheet 3 I INVENTOR Cf? I h/z'llz'am 1627c, 7

BY fl a:

ATTORNEY} Patented Mar. 21, 1933 UNITED STATES PATENT orrlca WILLIAM J. green, or DETROIT, mrcnrean, ASSI'GNOR 'ro Bonn Alarm & muss coaroaa'rron, or DETROIT, MICHIGAN, aconroim'rron or mcmom METHOD AND APPARATUS FOR TINNING CONNECTING ROD BEARINGS Application filed September 16, 1929, Serial No. 398,092.

The invention relates to a method and apparatus for tinning connecting rod bearings and the like.

- It is necessary in tinning the bearings of connecting rods and the like, prior to babbitting, to heat the portion to be tinned to bring the same to substantially the temperature of the molten tin prior to the tinning operation. It has heretofore beencustomary to do this either by placing the connecting rods in a heating furnace or submerging the bearing portion of the connecting r0 in the molten tin. The latter practice is probably preferable because by this method only. a portion of the rod, to wit, the bearing end which is submerged in the tin, is heated, and as a consequence the effect of the heat treatment, to which the connecting rod is subjected during its manufacture, is not affected.

No problems of consequence were encountered by this latter method when tinning single connecting rods, because the rod could be grasped by its wrist pin end and dipped. into the molten metal to the desired extent,

thereby maintaining the remaining portion of the rod free from contact with the molten tin.

It is commercially practicable and economically cflicient, however, to simultaneously tin and babbitt the two half bearing sections or ends of a pair of connecting rods. However, it is impossible from a practical standpoint to employ the dipping method of heating with a double connecting rod because it is impossible to submerge the bearing portions of the connecting rods without subjecting the remainder of the rods to the disastrous effect of the heated molten tin. Likewise it is economically impractical to heat the double connecting rod in a furnace because, as previouslypointedout, this heating of the connectingrods destroys the effects of the heat treatment to which the rod are subjectedduring manufacture.

It. is therefore oneof the primary objects of this invention to provide a method and means whereby the adjoining bearing portions of a double connecting rod may be heat d to the proper temperature by contact apparatus having a fixture for supporting a double connecting rod or a pair of connecting rods in operative proximity to a column of molten tin positively produced at a predetermined height by mechanical means such for instance as a centrifugal pump. In accordance with the present invention the molten tin is caused to flow upwardly through the opposed bearing surfaces of the double connecting rod and over the upper edge thereof and back into the pot or container. This heats the bearing surfaces of the connecting rods and brings the same to the desired temperature. The intimate contact of the column of tinnin I metal with the surfaces to be tinned exc udes the air which would cause oxidization, whereupon the surface to be tinned is brushed or scraped and a thorough union between the surface to be tinned and the tinning metal results. Thus the tinning operation is accomplished substantially automatically and without the aid of flux.

The apparatus to be described herein involves several novel details of construction and arrangement of parts, all of which, together with the manner in which my im-- proved method is practiced, will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawings, wherein Figure 1 is a side elevational view of a tinning machine constructed in accordance with my invention;

Figure 2 is a front elevational view of the structure illustrated in Figure 1;

Figure 3 is a fragmentary vertical sectional view, on a large scale, of the lower portion of the machine.

Figure 4 is a fragmentary elevational view taken substantially on the plane indicated by line 4'4' in Figure 3 of the connecting rod supporting fixture;

Figure 5 is a detailed sectionalview taken substantially on the plane indicated by line 5-5 in Figure 3; and V Figure 6 is a detailed sectional view taken substantially on the plane indicated by line 6-6 in Figure 3.

Referring now more particularly to the drawings, wherein like reference characters indicate like parts, it will be noted that there is provided a base 10 in which a tinning metal pot or container 11 is arranged. Suitable heating means -(not shown) is associated with the base 10 for maintaining the tinning metal in a molten state.

The super-structure comprises a main upright 12 carrying bearings 13 for a shaft 14.

Also carried by the upright 12 is a bracket or motor support 15 for a driving motor 16, the shaft 17 of which is provided with pulleys 18 and 19 respectively.

Connected to the shaft 14 for relative sliding movement is a pulley 20, with which a belt 21 engages, this belt passing around pulley 19.

- Suitably supported, as for instance by means of a frame member 22, is a pump shaft 23, the upper end of which carries a pulley 24 with which a belt 25 engages, this belt also passing around pulley 18 on the motor shaft 17.

Arranged within the tinning metal pot 11 is a pump, the casing of which is indicated generally by the reference character 26. This pump is preferably of the centrifugal t e.

The impeller blades 27 are carried by shaft member 28 which is secured to and forms a continuation of the pump shaft 23. The blades 27 rotate in a pump chamber 29,

which communicates with a substantially ,tangential passageway 30, which in turn connects with an upwardly extending spout or passageway 31. The bottom of the pump chamber is provided with an aperture 32 and the top of the pump chamber is closed by a removable cap or closure member 33.

The structure of this part of the pump can be best seen by a comparison of Figures 3 and 6, wherein it will be noted that the closure is provided with a notch 34 in its edge, adapted to clear an abutment or lug 35 when the closure is placed in position. The closure 33 is then given a partial rotation until 1t assumes a position substantially as illustrated in Figure 6, whereupon an abutment 36 in the nature of a wedge is driven into P position and engages the closure to hold thesame firmly in place. The closure member is rovided with an aperture 37 through which the pump shaft extends and it permits also of the entrance of the molten tin,

in the pump chamber.

By properly regulating the speed of the 'ump a column of molten metal can be proected a redetermined distance above the upper en of the spout 31. This condition clamp plate 39 for holding the connecting rods to be tinned. This plate is illustrated in plan view in Figure 4, and by comparison of Figures 3 and 4 it will be'noted that it is pivotally mounted adjacent one end at 40 to the flange 38. vThe other end is'provided with a handle 41 and intermediate the ends the plate is provided with a lateral enlargement or extension 42 which acts as a cover for the upper end of the spout 31 when the fixture plate 39 is moved to one position. In its other position the fixture plate is provided with an aperture 43 which registers with the spout 31, the two half bearing portions of the double acting rod being disposed over this aperture 43 of the fixture plate.

The fixture plate is preferably provided with acircular depression 44 (see particularly Figure 3), which surrounds aperture 43 and in which the enlargement or boss of the double acting rod C rests.- The fixture plate is provided with oppositely extending hook-like clips or abutments 45, so that the connecting rod C may be placed on the plate and then rotated about its center to bring the ends of the connecting rod under the clips 45. This will hold' the connecting rod in position, but obviously it may be readily removed from the fixture plate.

After positioning the connecting rod on the fixture plate the handle 41 whereof is grasped and the plate swung to a'pcsition wherein the aperture 43 thereof registers with the spout 31. During the other position of the fixture plate the cover 42 was disposed over the open upper end of the spout 31, so as to prevent the metal from flowing outwardly therefrom.

When, however, the aperture 43 in the plate and the two bearing portions of the connecting rods have been moved into registration wlth the spout, the metal is forced upwardly therefrom and into intimate contact with the surface of the bearing rod to be tinned. This metal flows upwardly over the upper edge of the bearing portion of the connecting rod and back into the pot 11, as will be obvious.

A guard 46 is provided surrounding the ot 11 to prevent the metal from splashing outwardly therefrom to injure the operator.

In order to. get an intimate and positive bond or union between the tinning metal and the bearing surface of the connecting rods to be tinned, it is necessary that the surface be ng tinned be brushed or scraped to thus remove any oxide or other foreign matter from this surface. If this is done while the surface to be tinned is in intimate contact with the column of tinning metal,

all air is excluded and the surface may be quickly and uniformly tinned. To this end the shaft 14, heretofore referred to, is provided with a surface engaging element here shown in the form of a rotary brush 47.

The main portion of this brush engages the' main'bearing surface C of the connectlng' rods, while the portion 48 of the brush engages the upper edge C" of the connecting rod. While a rotary brush of this character has been found to operate with the desired efficiency, other types of brushing or scrap ing means may obviously be employed.

The brush is normally held in a position clear of the connecting rod by means of a. weighted lever 48 pivotally connected, as at 49, to a part 50 of the frame or super structure of the device, the other end of the lever being pivotally connected as at 51 to the brush shaft 14 and being provided with a handle portion 52 and a weight 53 at the other extreme end. The brush shaft is mounted so as to permit of a limited universal movement so that the brush ma be brought into contact with all portions 0 the surfaces C and C". When the surfaces C and C" have been'tinned the fixture plate is moved to its other position and the connecting rod C turned over, so that the other portion corresponding to the surface C" may be tinned.

From the foregoing it is believed that the manner of operation of the machine and the manner in which the herein method is practiced will be apparent. By subjecting the bearing portions of the connecting rods to the action of the column of heated molten tin the surfaces to be tinned are brought to .the proper temperature but the heat is applied locally and only to those portions of the connecting rods which must be heated.

Thus the effect of the heat treatment to which the connecting rods are subjected during manufacture is not destroyed. The presence of this constant column of molten tin excludes all air from the surface being tinned and thus prevents oxidization. Moreover, by supplying a constant column of molten metal the temperature of the molten metalis maintained uniform, so that the surfaces being tinned may be quickly brought to the desired temperature. As a consequence, the connecting rod bearings maybe quickly and uniformly tinned and a thorough and efficient union or bond is obtained between the tinning metal and the connecting rod.

Obvious changes will suggest themselves to those skilled in this art, and to this end reservation is made to make such changes as may come within-the purview of the accompanying claims.

I claim as my invention:

1. In the method of tinning the bearing surfaces of heat treated connecting rods and contact with the said surface, and excluding air from contact with said surface by contact therewith of said column of tinning metal whereby said surface is tinned without oxidization.

2. A method of tinning connecting rod bearings and the like which consists in subjecting the bearing to the action of a column of molten tinning metal and simultaneously brushing the surfaces to be tinned in the presence of said column.

3. In the method of simultaneously tinning the annulus form by the large bearing ends of a pair of connecting rods, those ste s whichconsist in maintaining a substantially free column of hot molten tinning metal, bringing the annular surface to be tinned in registration with said column and brushing the said surface in the presence of said column. 7

4. The method of tinning circular bearing surfaces which consists in maintaining a free column of molten tinning metal, positioning the circular bearing surfaces over said column to cause the tinning metal to flow therethrough in intimate contact therewith, and brushing the surfaces to be tinned in the presence of the molten tinning metal to cause a union of the ti-nning metal and the surfaces to be tinned without oxidization. 5. Tnan apparatus of the class described, means for producing a column of molten tinning metal, means for supporting a surface to be tinned in the path of said column and means for checking said column without the cessation of said first mentioned means.

6. In a tinning machine of the character described, means including a centrifugal pump for producing a column of molten tin ning metal, a fixture plate for supporting a connecting rod or the like. in the path of said column and means carried by said fix ture plate for interrupting said column when said fixture plate is moved to one position.

7. In a tinning machine of the class described, a source of molten tinning metal, means including a pump for raising a column of tinning metal, a fixture plate for supporting the surfaces to be tinned in the path of said column, means for moving said fixture plate whereby to bring the surfaces to be tinned out of the path of said column and means carried by said fixture plate and acting in said latter position to interrupt said column.

8. In apparatus of the class described, means for producing and maintaining a free column of molten tinnin metal, a support fora connecting rod or t e like for holding the same in the path of said column, and

means actuated by movement of said support to one position for checking said free column of molten metal.

9. In the niethod of tinning annular' bear- 5 ing surfaces of connecting rods andthe like, the steps of maintaining a free column of heated molten tinning metal and bringing the annular surface to be tinned into registration with said column whereby the molten metal flows therethrough to exclude the air from said surface and heat and tin the said surface.

In testimony whereof I aflix my signature.

WILLIAM J, FIEGEL. 

